This year's heat is so intolerable and killing thousands of people across worldwide, now more than 1,300 people died during this year's Hajj pilgrimage in Saudi Arabia as the faithful faced extreme high temperatures at Islamic holy sites in the desert kingdom, Saudi authorities announced on Sunday.

Saudi Health Minister Fahd bin Abdurrahman Al-Jalajel said that 83 per cent of the 1,301 fatalities were unauthorised pilgrims who walked long distances in soaring temperatures to perform the Hajj rituals in and around the holy city of Mecca.

Speaking with the state-owned Al Ekhbariya TV, the minister said 95 pilgrims were being treated in hospitals, some of whom were airlifted for treatment in the capital, Riyadh.

He said the identification process was delayed because there were no identification documents with many of the dead pilgrims.

He said the dead were buried in Mecca, without giving a breakdown.

The fatalities included more than 660 Egyptians. All but 31 of them were unauthorised pilgrims, according to two officials in Cairo.

Egypt has revoked the licences of 16 travel agencies that helped unauthorised pilgrims travel to Saudi Arabia, authorities said.

The officials, who spoke on condition of anonymity because they were not authorised to brief journalists, said most of the dead were reported at the Emergency Complex in Mecca's Al-Muaisem neighbourhood. Egypt sent more than 50,000 authorised pilgrims to Saudi Arabia this year.

Saudi authorities cracked down on unauthorised pilgrims, expelling tens of thousands of people. But many, mostly Egyptians, managed to reach holy sites in and around Mecca, some on foot. Unlike authorised pilgrims, they had no hotels to return to escape the scorching heat.